A compact static infrared broadband snapshot imaging spectrometer (IBSIS) is presented. It consists of a telescope, three prisms, a focusing lens, and a detector. The first prism disperses sharply in the near-infrared (NIR) range along the vertical direction, and it is relatively non-dispersive in the mid-wave infrared (MWIR) range. The second prism is substantially more dispersive in the MWIR range than in the NIR range along the horizontal direction. The beam deviation caused by the first and second prisms can be controlled by the third prism. The IBSIS yields a two-dimensional dispersion pattern (TDP). The formulas and numerical simulation of the TDP are presented. The methods of target location calculation and spectral signature extraction are described. The IBSIS can locate multiple targets using only one frame of data, which allows for real-time detection and measurement of the energetic targets.